This invention relates to a core holder for reeling and method of making the same and, more particularly, to a unitary device which is used to support a parent roll of web material such as paper incident to converting. Illustrative of the field of application of the invention is the art of rewinding toilet paper and toweling. Such web material is provided in jumbo or parent rolls which may range up to 5 feet in diameter and 5 to 10 feet in axial length. These are the rolls that are removed from the paper machine and are usually transported to another section of the mill for conversion, i.e., unwinding, transverse perforation and rewinding into the well known commercial sized rolls.
As paper machines run faster and become wider, the diameter of the reel bar increases to overcome deflection and consequently, parent roll core diameters increase--this in turn, resulting in a requirement for larger diameter core plugs (inserts) for converting operations.
When preparing a parent roll for use on a converting machine, core inserts are manually pushed into each end of the parent roll core until a flange prevents further insertion. Each insert has extended "journals" which are used for hoisting and transporting the roll into a converting machine.
Each core insert has a relief in the end of its journal and when the parent roll--insert(s) assembly is properly positioned in an unwinding stand, this assembly is held fast between two rotatable spindles which have been pneumatically, slidably moved inward toward the parent roll and into the reliefs in said insert journals.
In conventional practice, steel core plugs (inserts) of about 11" diameter can weigh about 85 pounds and since these plugs must be handled manually when preparing a parent roll for converting, this fatiguing and difficult work is necessary everytime a parent roll change is required. This is not an infrequent occurrence inasmuch as many converting lines operate at the rate of about 2,000 feet per minute.
The invention makes use of a plastic core plug but one which differs substantially from the previously employed steel core plug. The prior art steel core plug had a stub tube axially connected to a much larger tube which in turn fitted within the paperboard core. Attempts to duplicate this in lighter weight plastic failed because of the inadequate strength of the plastic.
According to the instant invention, a first or inner tube is constructed of plastic and has adjacent to but spaced from one end a radially projecting flange. After this inner tube has been fashioned, there is molded about the tube a sleeve which is disposed primarily adjacent the other end and terminates a spaced distance from the tube flange. This sleeve is equipped with a plurality of longitudinally extending ribs, the ribs projecting radially outwardly from the sleeve. A flange is provided on the sleeve to cooperate with the tube flange in defining a socket or annulus for a lifting chain hook and the sleeve flange also rigidifies the ribs at the critical outer end thereof where stresses can be maximized. By virtue of molding the sleeve onto the inner tube, a variety of core plugs can be developed, depending upon the size of the mold. Also, because of the material of construction, it is relatively simple to grind down the ribs to predetermined radii so that a wide range of core insert sizes can be molded from a small number of molds.
Other objects and advantages of the invention may be seen in the details of construction and operation set down in the ensuing specification.